<template>
    <u-popup :maskCloseAble="maskCloseAble" mode="bottom" :popup="false" v-model="value" length="auto" :safeAreaInsetBottom="safeAreaInsetBottom" @close="close" :z-index="uZIndex">
        <view class="u-datetime-picker">
            <view class="u-picker-header" @touchmove.stop.prevent="">
                <view class="u-btn-picker u-btn-picker--tips" 
                    :style="{ color: cancelColor }" 
                    hover-class="u-opacity" 
                    :hover-stay-time="150" 
                    @tap="getResult('cancel')"
                >{{cancelText}}</view>
                <view class="u-picker__title">{{ title }}</view>
                <view
                    class="u-btn-picker u-btn-picker--primary"
                    :style="{ color: moving ? cancelColor : confirmColor }"
                    hover-class="u-opacity"
                    :hover-stay-time="150"
                    @touchmove.stop=""
                    @tap.stop="getResult('confirm')"
                >
                    {{confirmText}}
                </view>
            </view>
            <view class="u-picker-body">
                <picker-view v-if="mode == 'region'" :value="valueArr" @change="change" class="u-picker-view" @pickstart="pickstart" @pickend="pickend">
                    <picker-view-column v-if="!reset && params.province">
                        <view class="u-column-item" v-for="(item, index) in provinces" :key="index">
                            <view class="u-line-1">{{ item.label }}</view>
                        </view>
                    </picker-view-column>
                    <picker-view-column v-if="!reset && params.city">
                        <view class="u-column-item" v-for="(item, index) in citys" :key="index">
                            <view class="u-line-1">{{ item.label }}</view>
                        </view>
                    </picker-view-column>
                    <picker-view-column v-if="!reset && params.area">
                        <view class="u-column-item" v-for="(item, index) in areas" :key="index">
                            <view class="u-line-1">{{ item.label }}</view>
                        </view>
                    </picker-view-column>
                </picker-view>
                <picker-view v-else-if="mode == 'time'" :value="valueArr" @change="change" class="u-picker-view" @pickstart="pickstart" @pickend="pickend">
                    <picker-view-column v-if="!reset && params.year">
                        <view class="u-column-item" v-for="(item, index) in years" :key="index">
                            {{ item }}
                            <text class="u-text" v-if="showTimeTag">年</text>
                        </view>
                    </picker-view-column>
                    <picker-view-column v-if="!reset && params.month">
                        <view class="u-column-item" v-for="(item, index) in months" :key="index">
                            {{ formatNumber(item) }}
                            <text class="u-text" v-if="showTimeTag">月</text>
                        </view>
                    </picker-view-column>
                    <picker-view-column v-if="!reset && params.day">
                        <view class="u-column-item" v-for="(item, index) in days" :key="index">
                            {{ formatNumber(item) }}
                            <text class="u-text" v-if="showTimeTag">日</text>
                        </view>
                    </picker-view-column>
                    <picker-view-column v-if="!reset && params.hour">
                        <view class="u-column-item" v-for="(item, index) in hours" :key="index">
                            {{ formatNumber(item) }}
                            <text class="u-text" v-if="showTimeTag">时</text>
                        </view>
                    </picker-view-column>
                    <picker-view-column v-if="!reset && params.minute">
                        <view class="u-column-item" v-for="(item, index) in minutes" :key="index">
                            {{ formatNumber(item) }}
                            <text class="u-text" v-if="showTimeTag">分</text>
                        </view>
                    </picker-view-column>
                    <picker-view-column v-if="!reset && params.second">
                        <view class="u-column-item" v-for="(item, index) in seconds" :key="index">
                            {{ formatNumber(item) }}
                            <text class="u-text" v-if="showTimeTag">秒</text>
                        </view>
                    </picker-view-column>
                </picker-view>
                <picker-view v-else-if="mode == 'selector'" :value="valueArr" @change="change" class="u-picker-view" @pickstart="pickstart" @pickend="pickend">
                    <picker-view-column v-if="!reset">
                        <view class="u-column-item" v-for="(item, index) in range" :key="index">
                            <view class="u-line-1">{{ getItemValue(item, 'selector') }}</view>
                        </view>
                    </picker-view-column>
                </picker-view>
                <picker-view v-else-if="mode == 'multiSelector'" :value="valueArr" @change="change" class="u-picker-view" @pickstart="pickstart" @pickend="pickend">
                    <picker-view-column v-if="!reset" v-for="(item, index) in range" :key="index">
                        <view class="u-column-item" v-for="(item1, index1) in item" :key="index1">
                            <view class="u-line-1">{{ getItemValue(item1, 'multiSelector') }}</view>
                        </view>
                    </picker-view-column>
                </picker-view>
            </view>
        </view>
    </u-popup>
</template>

<script>
import provinces from '../../libs/util/province.js';
import citys from '../../libs/util/city.js';
import areas from '../../libs/util/area.js';

/**
 * picker picker弹出选择器
 * @description 此选择器有两种弹出模式：一是时间模式，可以配置年，日，月，时，分，秒参数 二是地区模式，可以配置省，市，区参数
 * @tutorial https://www.uviewui.com/components/picker.html
 * @property {Object} params 需要显示的参数，见官网说明
 * @property {String} mode 模式选择，region-地区类型，time-时间类型（默认time）
 * @property {String Number} start-year 可选的开始年份，mode=time时有效（默认1950）
 * @property {String Number} end-year 可选的结束年份，mode=time时有效（默认2050）
 * @property {Boolean} safe-area-inset-bottom 是否开启底部安全区适配（默认false）
 * @property {Boolean} show-time-tag 时间模式时，是否显示后面的年月日中文提示
 * @property {String} cancel-color 取消按钮的颜色（默认#606266）
 * @property {String} confirm-color 确认按钮的颜色（默认#2979ff）
 * @property {String} default-time 默认选中的时间，mode=time时有效
 * @property {String} confirm-text 确认按钮的文字
 * @property {String} cancel-text 取消按钮的文字
 * @property {String} default-region 默认选中的地区，中文形式，mode=region时有效
 * @property {String} default-code 默认选中的地区，编号形式，mode=region时有效
 * @property {Boolean} mask-close-able 是否允许通过点击遮罩关闭Picker（默认true）
 * @property {String Number} z-index 弹出时的z-index值（默认1075）
 * @property {Array} default-selector 数组形式，其中每一项表示选择了range对应项中的第几个
 * @property {Array} range 自定义选择的数据，mode=selector或mode=multiSelector时有效
 * @property {String} range-key 当range参数的元素为对象时，指定Object中的哪个key的值作为选择器显示内容
 * @event {Function} confirm 点击确定按钮，返回当前选择的值
 * @event {Function} cancel 点击取消按钮，返回当前选择的值
 * @example <u-picker v-model="show" mode="time"></u-picker>
 */
export default {
    name: 'u-picker',
    props: {
        // picker中需要显示的参数
        params: {
            type: Object,
            default() {
                return {
                    year: true,
                    month: true,
                    day: true,
                    hour: false,
                    minute: false,
                    second: false,
                    province: true,
                    city: true,
                    area: true,
                    timestamp: true,
                };
            }
        },
        // 当mode=selector或者mode=multiSelector时，提供的数组
        range: {
            type: Array,
            default() {
                return [];
            }
        },
        // 当mode=selector或者mode=multiSelector时，提供的默认选中的下标
        defaultSelector: {
            type: Array,
            default() {
                return [0];
            }
        },
        // 当 range 是一个 Array＜Object＞ 时，通过 range-key 来指定 Object 中 key 的值作为选择器显示内容
        rangeKey: {
            type: String,
            default: ''
        },
        // 模式选择，region-地区类型，time-时间类型，selector-单列模式，multiSelector-多列模式
        mode: {
            type: String,
            default: 'time'
        },
        // 年份开始时间
        startYear: {
            type: [String, Number],
            default: 1950
        },
        // 年份结束时间
        endYear: {
            type: [String, Number],
            default: 2050
        },
        // "取消"按钮的颜色
        cancelColor: {
            type: String,
            default: '#606266'
        },
        // "确定"按钮的颜色
        confirmColor: {
            type: String,
            default: '#2979ff'
        },
        // 默认显示的时间，2025-07-02 || 2025-07-02 13:01:00 || 2025/07/02
        defaultTime: {
            type: String,
            default: ''
        },
        // 默认显示的地区，可传类似["河北省", "秦皇岛市", "北戴河区"]
        defaultRegion: {
            type: Array,
            default() {
                return [];
            }
        },
        // 时间模式时，是否显示后面的年月日中文提示
        showTimeTag: {
            type: Boolean,
            default: true
        },
        // 默认显示地区的编码，defaultRegion和areaCode同时存在，areaCode优先，可传类似["13", "1303", "130304"]
        areaCode: {
            type: Array,
            default() {
                return [];
            }
        },
        safeAreaInsetBottom: {
            type: Boolean,
            default: false
        },
        // 是否允许通过点击遮罩关闭Picker
        maskCloseAble: {
            type: Boolean,
            default: true
        },
        // 通过双向绑定控制组件的弹出与收起
        value: {
            type: Boolean,
            default: false
        },
        // 弹出的z-index值
        zIndex: {
            type: [String, Number],
            default: 0
        },
        // 顶部标题
        title: {
            type: String,
            default: ''
        },
        // 取消按钮的文字
        cancelText: {
            type: String,
            default: '取消'
        },
        // 确认按钮的文字
        confirmText: {
            type: String,
            default: '确认'
        }
    },
    data() {
        return {
            years: [],
            months: [],
            days: [],
            hours: [],
            minutes: [],
            seconds: [],
            year: 0,
            month: 0,
            day: 0,
            hour: 0,
            minute: 0,
            second: 0,
            reset: false,
            startDate: '',
            endDate: '',
            valueArr: [],
            provinces: provinces,
            citys: citys[0],
            areas: areas[0][0],
            province: 0,
            city: 0,
            area: 0,
            moving: false // 列是否还在滑动中，微信小程序如果在滑动中就点确定，结果可能不准确
        };
    },
    mounted() {
        this.init();
    },
    computed: {
        propsChange() {
            // 引用这几个变量，是为了监听其变化
            return `${this.mode}-${this.defaultTime}-${this.startYear}-${this.endYear}-${this.defaultRegion}-${this.areaCode}`;
        },
        regionChange() {
            // 引用这几个变量，是为了监听其变化
            return `${this.province}-${this.city}`;
        },
        yearAndMonth() {
            return `${this.year}-${this.month}`;
        },
        uZIndex() {
            // 如果用户有传递z-index值，优先使用
            return this.zIndex ? this.zIndex : this.$u.zIndex.popup;
        }
    },
    watch: {
        propsChange() {
            this.reset = true;
            setTimeout(() => this.init(), 10);
        },
        // 如果地区发生变化，为了让picker联动起来，必须重置this.citys和this.areas
        regionChange(val) {
            this.citys = citys[this.province];
            this.areas = areas[this.province][this.city];
        },
        // watch监听月份的变化，实时变更日的天数，因为不同月份，天数不一样
        // 一个月可能有30，31天，甚至闰年2月的29天，平年2月28天
        yearAndMonth(val) {
            if (this.params.year) this.setDays();
        },
        // 微信和QQ小程序由于一些奇怪的原因(故同时对所有平台均初始化一遍)，需要重新初始化才能显示正确的值
        value(n) {
            if (n) {
                this.reset = true;
                setTimeout(() => this.init(), 10);
            }
        }
    },
    methods: {
        // 标识滑动开始，只有微信小程序才有这样的事件
        pickstart() {
            // #ifdef MP-WEIXIN
            this.moving = true;
            // #endif
        },
        // 标识滑动结束
        pickend() {
            // #ifdef MP-WEIXIN
            this.moving = false;
            // #endif
        },
        // 对单列和多列形式的判断是否有传入变量的情况
        getItemValue(item, mode) {
            // 目前(2020-05-25)uni-app对微信小程序编译有错误，导致v-if为false中的内容也执行，错误导致
            // 单列模式或者多列模式中的getItemValue同时被执行，故在这里再加一层判断
            if (this.mode == mode) {
                return typeof item == 'object' ? item[this.rangeKey] : item;
            }
        },
        // 小于10前面补0，用于月份，日期，时分秒等
        formatNumber(num) {
            return +num < 10 ? '0' + num : String(num);
        },
        // 生成递进的数组
        generateArray: function(start, end) {
            // 转为数值格式，否则用户给end-year等传递字符串值时，下面的end+1会导致字符串拼接，而不是相加
            start = Number(start);
            end = Number(end);
            end = end > start ? end : start;
            // 生成数组，获取其中的索引，并剪出来
            return [...Array(end + 1).keys()].slice(start);
        },
        getIndex: function(arr, val) {
            let index = arr.indexOf(val);
            // 如果index为-1(即找不到index值)，~(-1)=-(-1)-1=0，导致条件不成立
            return ~index ? index : 0;
        },
        //日期时间处理
        initTimeValue() {
            // 格式化时间，在IE浏览器(uni不存在此情况)，无法识别日期间的"-"间隔符号
            let fdate = this.defaultTime.replace(/\-/g, '/');
            fdate = fdate && fdate.indexOf('/') == -1 ? `2020/01/01 ${fdate}` : fdate;
            let time = null;
            if (fdate) time = new Date(fdate);
            else time = new Date();
            // 获取年日月时分秒
            this.year = time.getFullYear();
            this.month = Number(time.getMonth()) + 1;
            this.day = time.getDate();
            this.hour = time.getHours();
            this.minute = time.getMinutes();
            this.second = time.getSeconds();
        },
        init() {
            this.valueArr = [];
            this.reset = false;
            if (this.mode == 'time') {
                this.initTimeValue();
                if (this.params.year) {
                    this.valueArr.push(0);
                    this.setYears();
                }
                if (this.params.month) {
                    this.valueArr.push(0);
                    this.setMonths();
                }
                if (this.params.day) {
                    this.valueArr.push(0);
                    this.setDays();
                }
                if (this.params.hour) {
                    this.valueArr.push(0);
                    this.setHours();
                }
                if (this.params.minute) {
                    this.valueArr.push(0);
                    this.setMinutes();
                }
                if (this.params.second) {
                    this.valueArr.push(0);
                    this.setSeconds();
                }
            } else if (this.mode == 'region') {
                if (this.params.province) {
                    this.valueArr.push(0);
                    this.setProvinces();
                }
                if (this.params.city) {
                    this.valueArr.push(0);
                    this.setCitys();
                }
                if (this.params.area) {
                    this.valueArr.push(0);
                    this.setAreas();
                }
            } else if (this.mode == 'selector') {
                this.valueArr = this.defaultSelector;
            } else if (this.mode == 'multiSelector') {
                this.valueArr = this.defaultSelector;
                this.multiSelectorValue = this.defaultSelector;
            }
            this.$forceUpdate();
        },
        // 设置picker的某一列值
        setYears() {
            // 获取年份集合
            this.years = this.generateArray(this.startYear, this.endYear);
            // 设置this.valueArr某一项的值，是为了让picker预选中某一个值
            this.valueArr.splice(this.valueArr.length - 1, 1, this.getIndex(this.years, this.year));
        },
        setMonths() {
            this.months = this.generateArray(1, 12);
            this.valueArr.splice(this.valueArr.length - 1, 1, this.getIndex(this.months, this.month));
        },
        setDays() {
            let totalDays = new Date(this.year, this.month, 0).getDate();
            this.days = this.generateArray(1, totalDays);
            let index = 0;
            // 这里不能使用类似setMonths()中的this.valueArr.splice(this.valueArr.length - 1, xxx)做法
            // 因为this.month和this.year变化时，会触发watch中的this.setDays()，导致this.valueArr.length计算有误
            if (this.params.year && this.params.month) index = 2;
            else if (this.params.month) index = 1;
            else if (this.params.year) index = 1;
            else index = 0;
            // 当月份变化时，会导致日期的天数也会变化，如果原来选的天数大于变化后的天数，则重置为变化后的最大值
            // 比如原来选中3月31日，调整为2月后，日期变为最大29，这时如果day值继续为31显然不合理，于是将其置为29(picker-column从1开始)
            if(this.day > this.days.length) this.day = this.days.length;
            this.valueArr.splice(index, 1, this.getIndex(this.days, this.day));
        },
        setHours() {
            this.hours = this.generateArray(0, 23);
            this.valueArr.splice(this.valueArr.length - 1, 1, this.getIndex(this.hours, this.hour));
        },
        setMinutes() {
            this.minutes = this.generateArray(0, 59);
            this.valueArr.splice(this.valueArr.length - 1, 1, this.getIndex(this.minutes, this.minute));
        },
        setSeconds() {
            this.seconds = this.generateArray(0, 59);
            this.valueArr.splice(this.valueArr.length - 1, 1, this.getIndex(this.seconds, this.second));
        },
        setProvinces() {
            // 判断是否需要province参数
            if (!this.params.province) return;
            let tmp = '';
            let useCode = false;
            // 如果同时配置了defaultRegion和areaCode，优先使用areaCode参数
            if (this.areaCode.length) {
                tmp = this.areaCode[0];
                useCode = true;
            } else if (this.defaultRegion.length) tmp = this.defaultRegion[0];
            else tmp = 0;
            // 历遍省份数组匹配
            provinces.map((v, k) => {
                if (useCode ? v.value == tmp : v.label == tmp) {
                    tmp = k;
                }
            });
            this.province = tmp;
            this.provinces = provinces;
            // 设置默认省份的值
            this.valueArr.splice(0, 1, this.province);
        },
        setCitys() {
            if (!this.params.city) return;
            let tmp = '';
            let useCode = false;
            if (this.areaCode.length) {
                tmp = this.areaCode[1];
                useCode = true;
            } else if (this.defaultRegion.length) tmp = this.defaultRegion[1];
            else tmp = 0;
            citys[this.province].map((v, k) => {
                if (useCode ? v.value == tmp : v.label == tmp) {
                    tmp = k;
                }
            });
            this.city = tmp;
            this.citys = citys[this.province];
            this.valueArr.splice(1, 1, this.city);
        },
        setAreas() {
            if (!this.params.area) return;
            let tmp = '';
            let useCode = false;
            if (this.areaCode.length) {
                tmp = this.areaCode[2];
                useCode = true;
            } else if (this.defaultRegion.length) tmp = this.defaultRegion[2];
            else tmp = 0;
            areas[this.province][this.city].map((v, k) => {
                if (useCode ? v.value == tmp : v.label == tmp) {
                    tmp = k;
                }
            });
            this.area = tmp;
            this.areas = areas[this.province][this.city];
            this.valueArr.splice(2, 1, this.area);
        },
        close() {
            this.$emit('input', false);
        },
        // 用户更改picker的列选项
        change(e) {
            this.valueArr = e.detail.value;
            let i = 0;
            if (this.mode == 'time') {
                // 这里使用i++，是因为this.valueArr数组的长度是不确定长度的，它根据this.params的值来配置长度
                // 进入if规则，i会加1，保证了能获取准确的值
                if (this.params.year) this.year = this.years[this.valueArr[i++]];
                if (this.params.month) this.month = this.months[this.valueArr[i++]];
                if (this.params.day) this.day = this.days[this.valueArr[i++]];
                if (this.params.hour) this.hour = this.hours[this.valueArr[i++]];
                if (this.params.minute) this.minute = this.minutes[this.valueArr[i++]];
                if (this.params.second) this.second = this.seconds[this.valueArr[i++]];
            } else if (this.mode == 'region') {
                if (this.params.province) this.province = this.valueArr[i++];
                if (this.params.city) this.city = this.valueArr[i++];
                if (this.params.area) this.area = this.valueArr[i++];
            } else if (this.mode == 'multiSelector') {
                let index = null;
                // 对比前后两个数组，寻找变更的是哪一列，如果某一个元素不同，即可判定该列发生了变化
                this.defaultSelector.map((val, idx) => {
                    if (val != e.detail.value[idx]) index = idx;
                });
                // 为了让用户对多列变化时，对动态设置其他列的变更
                if (index != null) {
                    this.$emit('columnchange', {
                        column: index,
                        index: e.detail.value[index]
                    });
                }
            }
        },
        // 用户点击确定按钮
        getResult(event = null) {
            // #ifdef MP-WEIXIN
            if (this.moving) return;
            // #endif
            let result = {};
            // 只返回用户在this.params中配置了为true的字段
            if (this.mode == 'time') {
                if (this.params.year) result.year = this.formatNumber(this.year || 0);
                if (this.params.month) result.month = this.formatNumber(this.month || 0);
                if (this.params.day) result.day = this.formatNumber(this.day || 0);
                if (this.params.hour) result.hour = this.formatNumber(this.hour || 0);
                if (this.params.minute) result.minute = this.formatNumber(this.minute || 0);
                if (this.params.second) result.second = this.formatNumber(this.second || 0);
                if (this.params.timestamp) result.timestamp = this.getTimestamp();
            } else if (this.mode == 'region') {
                if (this.params.province) result.province = provinces[this.province];
                if (this.params.city) result.city = citys[this.province][this.city];
                if (this.params.area) result.area = areas[this.province][this.city][this.area];
            } else if (this.mode == 'selector') {
                result = this.valueArr;
            } else if (this.mode == 'multiSelector') {
                result = this.valueArr;
            }
            if (event) this.$emit(event, result);
            this.close();
        },
        // 获取时间戳
        getTimestamp() {
            // yyyy-mm-dd为安卓写法，不支持iOS，需要使用"/"分隔，才能二者兼容
            let time = this.year + '/' + this.month + '/' + this.day + ' ' + this.hour + ':' + this.minute + ':' + this.second;
            return new Date(time).getTime() / 1000;
        }
    }
};
</script>

<style lang="scss" scoped>
@import '../../libs/css/style.components.scss';

.u-datetime-picker {
    position: relative;
    z-index: 999;
}

.u-picker-view {
    height: 100%;
    box-sizing: border-box;
}

.u-picker-header {
    width: 100%;
    height: 90rpx;
    padding: 0 40rpx;
    @include vue-flex;
    justify-content: space-between;
    align-items: center;
    box-sizing: border-box;
    font-size: 30rpx;
    background: #fff;
    position: relative;
}

.u-picker-header::after {
    content: '';
    position: absolute;
    border-bottom: 1rpx solid #eaeef1;
    -webkit-transform: scaleY(0.5);
    transform: scaleY(0.5);
    bottom: 0;
    right: 0;
    left: 0;
}

.u-picker__title {
    color: $u-content-color;
}

.u-picker-body {
    width: 100%;
    height: 500rpx;
    overflow: hidden;
    background-color: #fff;
}

.u-column-item {
    @include vue-flex;
    align-items: center;
    justify-content: center;
    font-size: 32rpx;
    color: $u-main-color;
    padding: 0 8rpx;
}

.u-text {
    font-size: 24rpx;
    padding-left: 8rpx;
}

.u-btn-picker {
    padding: 16rpx;
    box-sizing: border-box;
    text-align: center;
    text-decoration: none;
}

.u-opacity {
    opacity: 0.5;
}

.u-btn-picker--primary {
    color: $u-type-primary;
}

.u-btn-picker--tips {
    color: $u-tips-color;
}
</style>
